1. Spallation Neutron Source Safety Program Overview
Samuel McKenzie
ESH Coordinator
Accelerator Systems Division
April 13, 2005

2. Spallation Neutron Source
SNS Site – 2004
The SNS will begin operation in 2006.
At 1.4 MW it will be ~8x ISIS, the world’s leading pulsed spallation source.
SNS will be the world’s leading facility for neutron scattering.
It will be a short drive from HFIR, a reactor source.

3. SNS will be World-Class!

4. SNS Accelerator Complex
Front-End: Produce a 1-msec long, chopped, low-energy H- beam
LINAC: Accelerate the beam to 1 GeV
Accumulator Ring: Compress 1 msec long pulse to 700 nsec
H- stripped to protons
Deliver beam to Target
Chopper system makes gaps
945 ns
mini-pulse
Current
Current
1 ms macropulse
1ms

5. SNS High Level Baseline Parameters
Proton beam energy on target GeV
Proton beam current on target 1.4 mA
Power on target 1.4 MW
Pulse repetition rate 60 Hz
Beam macropulse duty factor 6.0 %
H- peak linac current mA
Ring fill time ms
Ring beam extraction gap ns
Protons per pulse on target 1.5x1014
Proton pulse width on target ns
Linac length m
Total Beamline Length 903 m

6. Facility Parameters Area size of construction site 86 acres
Access and service roads 5 miles
Quantity of excavation at completion 1.5 MCY
Concrete 88,000 CY
Structural Steel 4,870 T
Electrical power (connected load) 78 MVA
Electrical power (operational demand) 49 MVA
Cooling water (heat load rejection) 37.4 MW
Cooling Tower water peak flow rate 21,000 gpm
Size of buildings and structures 616,000 sq ft
Site occupancy, including users, up to 500 persons

7. Target Systems
Converts up to 2 MW of 1 Gev Protons at 60 Hz into useful short neutron pulses.
Major Subsystems
Mercury target.
3 Supercritical hydrogen moderators with associated cryogenic systems and one ambient water moderator.
Beryllium reflector system.
Core vessel for target, moderator, reflectors.
10 m diameter iron shielding with shutters for neutron beams.
Utility systems including heavy and light water.
Remote Handling systems.
Instrumentation and controls.
Linac, Ring Injection and Ring Extraction beam dumps.

8. Target Building and Instrument Layout
18 - Wide Angle Chopper Spectrometer –
IDT DOE Funded –
Commission 2007
17 - High Resolution Chopper Spectrometer –
DOE Funded (SING) –
Commission 2008
13 - Fundamental Physics Beamline –
IDT Funding TBD –
Commission TBD
11A - Powder Diffractometer –
SNS Funded –
12 - Single Crystal Diffractometer –
Commission 2009
9 - Engineering Diffractometer –
IDT CFI Funded –
6 - SANS –
5 - Cold Neutron Chopper Spectrometer –
4A - Magnetism Reflectometer –
Commission 2006
3 - High Pressure Diffractometer –
2 - Backscattering Spectrometer –
1B - Disordered Mat’ls Diffractometer –
Commission 2010
PROTONS
4B - Liquids Reflectometer –
14B - Hybrid Spectrometer –
DOE Funded (SING) – Commission 2011
15 – Spin Echo
? – Chemical Spectrometer
60 m

9. Target Region Within Core Vessel
Target Module with jumpers
Outer Reflector Plug
Target Inflatable seal
Core Vessel water cooled shielding
Core Vessel Multi-channel flange

10. History of SNS
In 1998 DOE Broke Ground on the SNS with Critical Decision 4 (end of Project) in 2006
In 2000 the University of Tennessee and Battelle Teamed to win the Contract to Manage Oak Ridge National Lab.
Later that Year a “New” SNS Project Director was Hired and given Equal Status with the ORNL Lab Director.
A Stream-Lined Safety Program was Envisioned with Little if any ties to ORNL.
In 2002 a “New” Project Director was Hired and placed SNS Back Under the Direction of ORNL.

11. Standards Based Management System (SBMS)
A Proven System That Both PNNL and BNL Utilizes. Additionally INL will soon begin their Implementation Process.
Creates “One Stop Shopping” for Work Control and the Standards that the Work Shall and/or Should Follow
Clearly Defines ALL the Necessary Steps Needed to Perform a Certain Task.

12. Safety Overview
Since 2000, SNS (Non-Construction) has had 15 Recordable Injuries and Illnesses (RIIs) Cases and 1 Day with Restrictions Case (2002).
Additionally, ASD has 3 situations where there were violations of Internal Posting and/or Procedures (i.e. Lock Out Tag Out, Internal Parameters, etc.).
The injury rate at SNS remains exemplary (1.2 per 200,000 hours), and we must continue to strive for a continued safe work environment. In the coming months, we (SNS) will assume responsibility for the craft labor contract from Knight-Jacobs. This means we will be directly responsible for their attitude of, and commitment to, safety.

13. Safety Chain

14. Electrical Systems
By far our most dangerous activity is working on de-energized electrical systems, circuits and panels.
ASD has systems in every facet of its operation that utilizes high currents, voltages and/or capacitances!
A rigorous Lock Out Tag Out (LOTO) program is a must.
Our LOTO program serves us well and each group has a Safety Officer responsible for compliance with both NEC and SNS rules.
Additionally, we have offered over 10 Electrical Safety Classes that deal with the various aspects of our electrical equipment.

15. Research Safety Summaries
Research Safety Summaries (RSSs) are prepared at the Group and Lab Level.
Identify hazards a particular group is exposed to in their work.
Assist the Group Leader in determining the appropriate training and controls that need to be in place prior to performing work.
Defines the complete list of SBMS requirements for that Group.

16. Job Hazard Analysis
Job Hazard Analysis (JHA) - lynchpin of our Safety Program
process CLEARLY understood by all ASD employees and is the basis of Integrated Safety Management (ISM).
Work is defined in well understood steps.
Associated hazards determined at each step.
Action(s) established to mitigate hazards (i.e., safety glasses, erect a scaffolding, etc.).
Perform work within JHA guidelines.
JHAs are routinely reevaluated for completeness and enhancement.
Worker driven program with constant feedback on how we can continue to make the work safer.

17. ASD Example 1 Hoisting and Rigging
On Nov 5, 2001 An Employee at our old Receiving Facility was in the process of Lifting a Dipole Magnet when One of the Eye Bolts Failed.
As a Result of this Event we (ASD) instituted a Formal Process of Developing a Lift Plan for all our Lifts. A detailed JHA is Prepared and the Documentation is reviewed by one of a Select Group of Mechanical Engineers
The Lab’s Program is Modeled after ours and Our External Accelerator Review Committee has made several statements complimenting us on the rigor and completeness of our Hoisting and Rigging Program

18. ASD Example 2 Lock Out Tag Out
On Nov 22, 2002 An Employee was inspecting a Lock and Tag applied to a Circuit Breaker in the Klystron Building when the tag came off in the employee’s hand. The incident was not properly reported.
As a Result of this Event we (ASD) immediately provided a LOTO Practical Factors Training Program for all Affected Employee. As a result of finding additional deficiencies we provided LOTO Verification Training.
ASD has always employed the OSHA Required Equipment Specific LOTO Process. The lab’s program now employs this process as well.

19. Where There’s Smoke…..There’s not ALWAYS A Fire!
On Sept 9, 2004 An Evacuation of the Linac Tunnel, Klystron Gallery and Front End Building Occurred while we where Commissioning our Warm Accelerator (~150 MeV). This evacuation was due to Our Early Detection Smoke Alarm System.

20. Smoke Event Cont’
This evacuation occurred due to a Cryogenic Gas System heater being in close Proximity to Canvas Bags containing Steel Shot that is used for shielding Purposes. The 2 kW Heater is normally used during the Initial Cryomodule fill process. For our 4 Kelvin cool down the system remained in place ~1 month. Due to Thermocouple Placement and other factors the system did not respond properly and cause the pipe to Overheat.

21. Smoke Event cont’
This Overheating never caused an open flame fire but did burn several Canvas Bags that Held the Steel Shot.

22. Conclusion
SNS has done a wonderful job of developing a concise system embracing SBMS and ISM to build a world class accelerator facility!
We have to continue to learn from our own mistakes and from others.
We have to be open and honest about our mistakes as well as our successes.
We must Continue to understand what we want to do before we perform the Work (ISM).
We have to recognize that the hazards within our divisions continue to increase as we go into operation with more and more very powerful equipment
We have to be aware, that we share issues. Perform work in offices, storage buildings etc that carry their own risk, which usually is not as obvious as the technical ones.